diff options
| author | erifan01 <eric.fang@arm.com> | 2019-02-11 09:40:02 +0000 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2019-03-07 13:37:54 +0000 |
| commit | fee84cc90542884edda60d3eec2cd47f72d67118 (patch) | |
| tree | 0193c9781e52c6b2f18977f84718546e68dcd4de /test/codegen/mathbits.go | |
| parent | a2ace8ec18a833e5d286e4e9af6fc5de41ca9a31 (diff) | |
| download | go-fee84cc90542884edda60d3eec2cd47f72d67118.tar.xz | |
cmd/compile: add an optimization rule for math/bits.ReverseBytes16 on arm
This CL adds two rules to turn patterns like ((x<<8) | (x>>8)) (the type of
x is uint16, "|" can also be "+" or "^") to a REV16 instruction on arm v6+.
This optimization rule can be used for math/bits.ReverseBytes16.
Benchmarks on arm v6:
name old time/op new time/op delta
ReverseBytes-32 2.86ns ± 0% 2.86ns ± 0% ~ (all equal)
ReverseBytes16-32 2.86ns ± 0% 2.86ns ± 0% ~ (all equal)
ReverseBytes32-32 1.29ns ± 0% 1.29ns ± 0% ~ (all equal)
ReverseBytes64-32 1.43ns ± 0% 1.43ns ± 0% ~ (all equal)
Change-Id: I819e633c9a9d308f8e476fb0c82d73fb73dd019f
Reviewed-on: https://go-review.googlesource.com/c/go/+/159019
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'test/codegen/mathbits.go')
| -rw-r--r-- | test/codegen/mathbits.go | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go index cc3c91eb0d..09939bb6be 100644 --- a/test/codegen/mathbits.go +++ b/test/codegen/mathbits.go @@ -171,6 +171,9 @@ func ReverseBytes32(n uint32) uint32 { func ReverseBytes16(n uint16) uint16 { // amd64:"ROLW" // arm64:"REV16W",-"UBFX",-"ORR" + // arm/5:"SLL","SRL","ORR" + // arm/6:"REV16" + // arm/7:"REV16" return bits.ReverseBytes16(n) } |